<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <!-- 注意 vue-resource 依赖于Vue 所以先后顺序不能反 -->
    <!-- this.$http.jsonp -->
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script src="https://cdn.bootcss.com/vue-resource/1.5.1/vue-resource.js"></script>
</head>
<body>
    <div id="app">
        <input type="button" value="toggle" @click="flag=!flag">
        <!-- 需求：点击按钮，让h3显示，再点击，让h3隐藏 -->
        <h3 v-if="flag">这是一个h3</h3>
    </div>

    <script>
        var vm = new Vue({
            el: '#app',
            data: {
                flag: false
            },
            methods: {
            }
        })
    
    </script>
</body>
</html>
